The present invention relates to a method for providing a toughening treatment for metallic material by making use of transformation super-plastic phenomena.
Heretofore, heat treatment of metallic materials has been conducted in various ways to enhance the mechanical strength and to improve toughness of metallic materials, including steel. However, most of the prior methods were heat treatments at elevated temperature extending over a long period of time because the aim was to disperse and separate non-metal interstitial substances such as carbides.